Definition

1. Noun:
   • A type of lymphocyte: A B cell is a white blood cell that originates in the bone marrow. It is a crucial component of the adaptive immune system, responsible for humoral immunity.
   • Function in immunity: Its primary role is to recognize specific foreign molecules (antigens) and, upon activation, mature into plasma cells that produce antibodies to neutralize those antigens.

Usage Examples

• Noun:
  • The vaccine works by stimulating the body's B cells to produce protective antibodies.
  • A deficiency in B cells can lead to an increased susceptibility to infections.

Advanced Usage

• Memory B cell: A long-lived B cell that "remembers" a specific antigen, allowing for a faster and stronger immune response upon re-exposure.
  • After an infection, memory B cells remain in the body to provide long-term immunity.
• B cell receptor (BCR): The specialized protein on the surface of a B cell that binds to a specific antigen.
  • The B cell receptor is essential for antigen recognition and B cell activation.

Variants and Related Words

• B lymphocyte: A full synonym for B cell.
• Plasma cell: The terminally differentiated, antibody-secreting cell into which an activated B cell matures.
• Humoral immunity: The aspect of immunity mediated by macromolecules (like antibodies) found in extracellular fluids, which is the primary function of B cells.

Synonyms

• B lymphocyte: The formal, equivalent term.
• Antibody-producing cell: A descriptive term highlighting its end function, though this more precisely refers to its mature form, the plasma cell.

Related Phrases

• B cell activation: The process by which a B cell is stimulated by an antigen (often with help from other immune cells) to proliferate and differentiate.
  • T helper cells are required for full B cell activation.
• B cell maturation: The development of B cells in the bone marrow and their subsequent functional development in the immune system.

Related Idioms

There are no common idioms specifically for "B cell" as it is a technical, scientific term. Its usage is confined to biological, medical, and immunological contexts.

Noun

1. a lymphocyte derived from bone marrow that provides humoral immunity; it recognizes free antigen molecules in solution and matures into plasma cells that secrete immunoglobulin (antibodies) that inactivate the antigens